Nipple's Replacement

Had to edit..


How often do you guys replace your bottle's nipple? 

my son changed his nipple flow every few months.. so thats how often its changed. i dont know how often yuo are supposed to change it.. but id say if you see signs or wear or weakness change it.. or scratches because you dont want becteria to grow in crevases. but personally i think you could just steam sterilize or boil the nipples to make sure theyre alright. you just dont want them to weaken and have him pull the nipple out and get the milk all over the place. lol.